fix: VERSIONING_GIT_TAG will simulate no branch

Author: qoomon

build.gradle

@@ -11,7 +11,7 @@ plugins {
 }
 
 group 'me.qoomon'
-version '1.2.2'
+version '1.2.3'
 
 sourceCompatibility = JavaVersion.VERSION_1_8
 targetCompatibility = JavaVersion.VERSION_1_8

src/main/java/me/qoomon/gradle/gitversioning/GitVersioningPlugin.java

@@ -26,14 +26,15 @@ public void apply(@Nonnull Project rootProject) {
         rootProject.afterEvaluate(evaluatedProject -> {
 
             GitRepoSituation repoSituation = GitUtil.situation(rootProject.getProjectDir());
-            String providedBranch = getOption(rootProject, "git.branch");
-            if (providedBranch != null) {
-                repoSituation.setHeadBranch(providedBranch.isEmpty() ? null : providedBranch);
-            }
             String providedTag = getOption(rootProject, "git.tag");
             if (providedTag != null) {
+                repoSituation.setHeadBranch(null);
                 repoSituation.setHeadTags(providedTag.isEmpty() ? emptyList() : singletonList(providedTag));
             }
+            String providedBranch = getOption(rootProject, "git.branch");
+            if (providedBranch != null) {
+                repoSituation.setHeadBranch(providedBranch.isEmpty() ? null : providedBranch);
+            }
 
             GitVersionDetails gitVersionDetails = GitVersioning.determineVersion(repoSituation,
                     ofNullable(config.commit)